chittenden-and h



F. CHITTENDEN AND H. S. FOLKER.

RAILWAY mam CONTROL MECHANISM.

APPLICATION FILED 0CT.28| 1318.

1,334,520, Patented Mar. 23, 1920.

3 SHEETS-SHEET I.

Z0 3 @3214;- BY #400415? p566 Qua. @1922,

A TTORNEYS.

F. CHITTENDEN AND H. S. FULKER. RAILWAY TRAIN CONTROLMECHANSM.

APPLICATION FILED our. 2:], 2918.

1,334,520, Patelited Mar. 23, 1920.

3 SHEETS-SHEET 2.

WITNESS:

INVENTORS BY AM 8% A TTORNE YS.

F. CHITTENDEN AND H. S. FOLKER.

RAILWAY TRA'N CONTROL MECHANISM.

APPLICAHON FILED 'OCT. 28, I918.

Patented Mar. 23, 1920.

3 SHEETS-SHEET 3 HYVEIYTORQ 'A TTOR NE YS.

keeper automatical UNITED STATES PATENT OFFICE.

FOBEE CHITTENDEN. OF OAKLAND, AND HOWARD S FOLKEB, OF SAN CALIFORNIA,ASSIGNOBS TO NATIONAL SAFETY APPLIANCE COMPA NOISCO, OF 'BAN FRANCISCO,CALIFORNIA, A COBI'OBATION 01' CALIFORNIA.

RAILWAY-TRAIN-CONTROL MECHANISM.

Specification of Letters Patent. Patented Mar. 23, 1920,

Application flied October 28. 1918. Serial No. 259,942.

To all whom it may couccrn:

Be it known that we, F 0am: Curr'rnnnsx and HOWARD S. FOLKER, citizensof the United States, said Cm'rrexonx a resident of Oakland, in thecounty of Alameda and State of California, and said Fomum a resident ofthe city and county of San Francisco, State of California, have inventedcertain new and-useful Improvements in Railway -Train-C0ntrol Mechanism,of which the following is a specification.

The present invention relates to a means for establishing acommunication between a roadway and a railway vehicle, wherebycomplicated electrical mechanism and intricate wiring systems aredispensed with and a simple magnetic ap iratns, the op eration of whichis contro led by suitable permanent track magnets, is provided.

The principal objects of the invention are to provide an apparatuscapable of being operated solely by magnetism at any desired point on arailway at which is positioned a controlling member, but ll'lOlBparticularly at a block entrance, the operation of said apparatus beingdependent on the position of the keeper for the permanent controllingmagnet, and to provide, further, an a paratus which is capable ofoperation on t e movement of the vehicle in either direction. andwhereby the vehicle air line may be so operated or controlled that asignal] may be transmitted to .the vehicle operator, or the furthermovement of the vehicle may be automatically ctintrollcd either byoperating the brakes controlling the throttle or in any other desiredmanner.

The invention consists In-badly in a permanent track magnet providedwith a movable y or manually operated and relatively t which is movable,by the movement of the vehicle, a suitable member or signal receivingmechanism normall) held in inoperative position by the magnetic flux ofa suitable comparatively weak. magnct associated therewith, the signalreceiving mechanism bein moved to operative position by the ncutra izingof the magnetism thereof on the movement of the same ovcr the pcrmanentmagnet when the keeper thereof is in open position.

With the above mcnt' mod and other objects in view, the inventionconsists in the novel (Ollfillllutl-Ii and combination of partshereinafter described, illustrated in the accompany-in drawings and theclaims ereto appended; it being understood that various changes in theform, proportion, size, and minor details of construc tion within thescope of the claims may be resorted to. without departing from thespirit or sacrificing any of the advantages of the invention.

To more fully comprehend the invention, reference is directed to theaccompanying drawings, wherein- Figure 1 is a diagrammatic view of asectionof a railway illustrating the permanent track magnets at theentrance and exit of the block oi! a single track railroad and ailsrailn control unit carried by the railway venc e. c. Fig. 2 is aview' in side elevation of a section of a railway and aportion of thevehicle, with the preferred embodiment of our invention illustrated inconnection therewith. H1

. Fig. 3 is a length dinal sectional view of the vehicle unitillustrating the signal reccivcrs and the corrector.

Fig. l is a vertical sectional view of one of the receivers taken online 4-4 of Fi 3.

Fig. 5 is a vertical sectional view ta on on line of Fig. 4.

Referring more particularly to the drawings, wherein like characters ofreference designate correspondin parts, a railway is indicated in Figs.1 am 2 in which the rails l arc preferably divided in any suitablemanner. as by insulations 2 intd blocks A and B. At the entrance of eachblock is positioned preferably between the rails 1, a permanent magnet4. having a movable keeper 5 automatically or manually operated by anytype of mechanism, either controlled from a tower or by the movement ofthe vehicle from block to block, one form of mechanism bein illustratedin pendih ap-,

plication Serial; umber 223,281, filed arch 19, 1918.

In the illustration in Fig. 1 a single track railway is illustrated toaccommodate the movement of trains in jboth directions, andl in such aninstallation a permanent magnet is provided at each end of each block,the

ointed out in ad acent magnets of abutting blocks facing each other withtheir poles reversed.

The pcrmancnt magnet 4 as illust ted in the drawing, is considerablylarger than the magnetic means carried by the vehicle hereinafterdescribed, and owing to its increased size the same is of greater powerthan said hereinafter described magnetic means in order to insure thecorrect operation of the various elements.

Operating on the rails 2 is a vehicle truck 6 supporting a suitablevehicle 7, the truck carrying an operating unit 8 disposed to pass overthe permai'lent magnets within the magnetic field thereof during themovement of the vehicle thereover.

The unit comprises an elongated plate or bed member 9 disposed parallelwith the rails and depending from the said plate at its opposite endsare the hollow signal receivers .10, each having interposed ahead 11between its upper open end and the underside of member 9 (Figs. 3 and lof the drawings). The heads are each provided with a cen trally disposedopening 12, within which is mounted the tubular bushing 13 'having aseat 14 therein, on which rests a flexible valve seat or disk 15 held inposition on the seat by a suitable retaining ring 16, the valve seatbeing formed with the opening 16 in its center smaller than the openingafiorded by the seat 14. An air' release port 17 is provided in thebushing 13 below the seat 14, and from the same extend the laterals 18leading through the head to the atmosphere (Fig. 4 of the drawings).

At a point below'the port 17 15 mounted in the underside of the tubularbushing a tubular valve guid 19, in which reciprocates the upper end ofa; valve 20 carrying at its lower end the armature 21, coi'iperatingWltll the poles of an electromagnet 22. The'yoke 23 of the magnet isformed with a tubular bore 24 in which is held the uide 19. and throughwhich passes the vfilve 2Q. The magnet is normally maintained energiaedby a. batter 5 (Fig. 2 of the drawings) in circuit therewith thrmig'hleads 26', and pre'l erably carried by the vehicle. The tubular bushing;l3 communicates with the lateral air supply 26 formed in the bed 9 andleading from the main supply duct 30, connected with the train air line31; Fig. 1. of the V drawings, valve 31'.

T he valve 20 guided in its movement by a stationary pin 32 (Fig. 4 ofthe drawings) passing through. an opening 33 In the armature 21. thevalve when iniseated m sting on a spring pressed plunger 3i mounted in aguide 35 carried by a closui'c plate secured to the lower 0nd of eachsignal receiver.

Each plunger normally forced upwardly by a coiled spring 37 (Figs. 3 and4 of the and whiclris controlled by a drawings) within the guide 35, andwhirh is adapted to restore the valve to closed posh tiou after the airsupply under pressure has been momentarily shut oil 1 the air line 31.

The energizing of the magnet ilfi is suf- Ticient to maintain the valve20 in closed position against the underside of the flexible member 15.However, on the momentary reversing of the magnetism of the magnet 22 bythe magnetic field of one of the. permanent magnets 4, the slightestdownward movement of the valveQO will expose the valve area of the upperend thereof to the air pressure in the lateral 26, and which airpressure is sufficient to maintain the valve ownwardly pressediagainstthe action of the spring S7,.and power of magnet 22, permitting the airfrom line 31 to escape through the outlets 18, until. such time as theair pressure isinterrupted in lateral 26, when the spring 37 will movethe valve to closed position seating the upper end thereof against theunderside of the disk 1.5 formed with the opening 16 of an area lessthanthe area. of the valve end, thus reducing the area of the valve endexposed to the air pressure, enabling the magnet 22 to maintai'nthe'armatnre 21 in engagement therewithholding the valve end inst theunderside of the flexible mem r 15. The member 15 being flexible, isforced by the air pressure against the end of valve 20, maintaining a tiht seal thereover at all times during, the seating of the valve mem- .r.

From the magnet extend the pole pieces 38 projecting outwardly fromtheieceivers 10 to overhe the poles of the permanent track ma -nets 4 andcarrying on their ends shoes 39 F ig. 4 of the drawings), the poles ofthe magnets of the res ective rece vers being reversed from each at er,as in Fig. 1, so that the poles of the last receiver in the direetionoftravel of the vehicle will lie reversed to the oles of the ermanenttrack magnet of. the look into w ich the vehicle is moving. A safetychannel 36 (Fig. 3 of the drawings) extends from the outer end of eachlateral 26 throughthe receiver 10, said channels each being closed atits lower end bv the plates 36, thus insuring an opening 0 the air ]ineon the accidental removal or fracturing of the plate or receiver casing.

Secured to theunderside of the bed memher 9, between the signalreceivers 10;. is a. signal corrector 40 (Figs. 3 and 5 of the drawings)in the form of a shell 41, open it its upper end and closed at its lowerend. Within the upper open end of the shell is received the member 41formed with the main bore 42 therein, communicating at one end with themain supply duct 30 and laterally from the lower end of said bore extendthe bores 43 (Fig. 3 of the drawings), one

communicating at its discharge end with the inlet end of one of thelateral supply ducts 26.

upward movement thereof to be received in thereby enabling said bore andclose the same. The valve operates at its lower end in a guide 451:

igs. 2i and 5 of the drawings) and carries an armature or plate l5normally lying below the spaced inner ends of ma netic conductor arms*6, the outer ends of which ex tend laterally from opposite sides of thelower endot shell 41 and carry conductor shoes H. The Corrector valve 41is adapted to be operated by magnetism of any polarity to close the bore43 and interru t the flow of air therethrough. Hence it wi 1 beunnecessary to operate valve 31' in orderto inter rupt the flow of airin bore 43, enabling any installation of the double receiver type withthe corrector interposed between the same to operate on a single ordouble track system, as, for example. in the system illustrated in Fig.1.

Should, for any reason, the keeper of the magnet of the block thevehicle is leaving be disengaged from its magnet, as for example due tothe operation of the keeper controlling means one form of which isillustrated in copending application Serial No. 223,281, and which blockmagnet is for controlling the entrance of vehicles traveling in anopposite direction on entering the block, the first receiver in thedirection of travel of the vehicle will be operated. Immediatelythereafter the corrector. valve will be operated, shutting off the airsupply and permitting of the automatic restoring of the valve ottheoperated receiver to normal position,

the correct signal to be communicated to the last receiver on the samepassing into the block the vehicle is entering or is about to enter.

The arts being assembled as in the drawings, t e operation of theapparatus is as follows z- The vehicle moving in the direc tion of thearrow 50, Fig. 1', from block A to block B, the signal receiver C of-theunit will first pass over the permanent track magnet l at one end of theblock A, the poles of which are reversed to the poles of the magnet ofreceiver C. Should for any reason the keeper 5 of said magnet bedisconnected from the poles thereof, creating a magnetic field inproximity to said poles, the valvepf the receiver C will be operated,opening the air line 31 to the atmosphere. However, inasn'iuch as thisreceiver is dc signed for controlling the opening of the airlinc to theatmosphere on the movement of the vehicle in a direction reverse in the.

arrow 50, this opening of the valve 20 of the receive: C is immediatelycorrected by the operation of the valve 44 of the signal co1-- rect rimmediately following the receiver C oven-Jilin permanent magnet 4, theoperation of the corroctor valve nunncntarily and automaticallyinterrupting the air-pressure from line 31. permitting the valve 20 ofsignal receiver G to assume its closed position. If

. operate as block B is clear or unoccupied the keeper of magnet l atthe entrance thereof will con nect the poles of said magnet, and thereceivers C and D to the corrector will pass thcreover withoutoperation.

Assuming the block B to be occupied, the keeper of the nmguct l at theentrance thereof is adapted to he moved by its operating means set.forth in the before mentioned copendin application Serial No. 223,281 tolie in utted line position-Fi 2, permitting the creating of a magneticeld at the ends of the poles thereof.

On the passin of the receiver C within the magnetic fie d of said magnetnumeral 4: of block B, the valve thereof will not be operated, as thepoles of said receiver and magnet coincide, as do the poles of the re:ccivcr I) and the magnet at the end of the block A the vehicle isleaving. The corrertor will be operated on passing over said inagn t asthe same has no polarity. However, t e 0 ration of the Corrector isimmaterial, as t e receiver in advance thereof has not been operated.The receiver I) passing within the magnetic lield of the magnet 4 at theentrance of the block B will be caused to the poles thereof are icversedto the poles of said magnet, the force of which neutralizes themagnetism of the magnet 2:3 holding the valve thereof closed, permittingthe air ressure in line 31 to act against the end of t 1e valve 20 andunseat the same during the momentary passaga of the receiver 1) oversaid magnet 4 of block B, when the vehicle is traveling in the directionof the arrow 50. The air thus released escaping through laterals 18,during which time the air-line 31 is open to the atmosphere, and whichoperation continues until such time as the vehicle operator momentarilycloses the valve 31', at which time the spring 37 forces the valveupwardly, cutting off the escape of the air through lateral 18 andpositioning the armature 21 of said valve within the field of magnet 22,which is of sutlicient power to retain said armature in Contacttherewith to maintain the valve closed.

In the piescnt itpplication it will be apparent that the perinaucnttrack magnet at the entrance of the block toward which the vehicle istraveling is the one which controls the release of piessure in theair-line to the atmosphere, and this magnet when its associated keeperis removed from the poles thereof operates the last receiver of the unitpassing over the same. Regardless of the direction of travel of thevehicle the corrector is operated by the magnctism'ot' any permanentmagnet l, the keeper of which is disconnected from the poles thereof.llowcver, as this col-rector passes within the magnetic field of anygiven track magnet immediately after the first receiver of the unitpasses over the magnet, the corrector immethereof for controlling themagnetic field adjacent to the ends of said poles, a signalrcecivervcarried by :urailway vehicle and movable within the magneticfield of said permanent track magnet, polarized magnetic means arrangedwith the poles thereof reversed to the poles of said track magnet andfor normally maintaining said signal means in inoperative position, saidtrack ma net adapted on the creation of a magnetic cld around the polesthereof and on the movement of said signal receiver within the mag'netic field thereof to neutralize the magnetism of said magnetic meansto )ermit operation of said signal, and means i'or restoring said signalreceiver to normal inoperative position on the movement of the samewithout the m etic field of said track magnet.

6. A rai way signal system including a permanent polarized track magnet,a signal receiver carried by a railway vehicle and movable within themagnetic field of said permanent track magnet, polarized magnctic meansfor normally maintaining said signal means in, inoperative osition andarr with its poles reverse to the poles of said track magnet, saidtrack' magnet adapted on the movement of said signal receiver within themagnetic field thereof to neutralize the magnetism of said magneticmeans and permit operation of said signal, manually controlled means caable of operation to permit the restoring 0 said receiver to normalinoperative position on the movement of the receiver without themagnetic field of said permanent track magnet, and means associated withthe poles of said track magnet for controlling the magnetic field adjaoent the ends of and poles.

A railway signal system including a signal receiver, p0 magnetic meansfor retaining the same in inoperative position, a permanent polarizedtrack magnet of greater than said magnetic means and arranged with itspoles reversed and the has of said magnetic means and lwithin t e fieldof which said receiver is movable, said nnanent magnet on able ofneutralizing t e ma etism of sai signal receiver to permit 1; cautomatic operation thereof and means disposed at the endsi pf the polesof the permanent track magnet for controlling the magnetic fieldadjacent the ends of t e poles of said permanent track magnet.

8. A railway signal system including a. polarized magneticallycontrolled signal are ceiver, a, permanent 111 et within the field ofwhich said receiver is movable and with les of said re its polesreversed to the ceiver magnet for neutra izing the flingnetism of saidsignal receiver, means 'ciated with the po es of the track magnet orcontrolling the magnetic field adjacent the ends of said poles, andmeans associated with said signal receiver for operating the same on theneutralizing of the magnetism thereof.

9. A railway signal system including a. polarized magnetic controlledsignal receiver, a permanent magnet within the field of which saidreceiver is movable and with its poles reversed to the poles of saidreceiver magnet and capable of neutralizing the magnetism within saidsignal receiver, means associated with said signal receiver foroperating the same on the neutralizing of the magnetism thereof andmeans for restoring the signal receiver to normal position on theinterruption of said last mentioned 80 means and the movement of saidreceiver without the magnetic field of said permanent magnet. a

10. A railway signal system including a signal receiver, a movablesignal control member therein, polarized magnetic means for maintainingthe same normally in inoperative position, a permanent polarized trackmagnet within the field of which said receiver is movable, said magneticfield being capableof neutralizing the magnetism of said magnetic meansassociated with said movable member to permit the operation of saidmovable member. and means associated with the oles of said permanentmagnet for contro ling the magnetic field adjacent the ends of the polesof said permanent track magnet.

11. A railway signal system including a signal receiver, a movable si a]control member therein, an airline having an escape and within whichsaid movable member is mounted to normally maintain the same closed,magnetic means for retaining said movable member in a osition to closesaid line, a. rmanent trac magnet and its associa keeper within thefield of which said receiver is movable, said kee r controlling thefield of said magnet, sai magnet being capable on the disengagement ofthe keeper t erefrom of neutralizing the mag netlsm of said magneticmeans associated with said movable member to permit the operationthereof by said air under pressure, manually controlled means withinsaid air line for mterruptin the pressure therein to permit the autom 10closing of said movable member on the movement of the receiver withoutthe magnetic field of said perma. nent track magnet. 7

12. A railway signal system including a signal receiver carried by arailway vehicle movable signal control means associa therewith, ma eticmeans for normally maintaining and member in inoperative position, apermanent track magnet within the magnetic field of which saidreceiveris movable and adapted to neutralize the magnetism of, saidmagnetic means, means under mally maintaining t trol means on theneutralizing of said magmagnet, and means associated with the poles ofsaid track magnet for controlling the magnetic field adjacent the endsof the poles of said track magnet.

13. A railway signal system including a polarized permanent trackmagnet, a signal receiver member carried by a railway vehicle andincluding a pair of receiver units, a movable signal control member.within each of. said units, magnetic means associated with each of saidsi nal receivers for nore movable signal control member therein ininoperative position, the poles of said magnetic means being reversedrelatively to each other, and the poles of one being reversed relativelyto the poles of said permanent track magnet, whereby on the movement ofsaid vehicle within the magnetic field of said permanent track magnetthe magnetism controlling the movable signal control member, the polesof which are reversed to the poles of said permanent track magnet may beneutralized, permitting the automatic operation of said control member,and means for controlling the field of said track magnet.

14, In combination with a railway vehicle air-line, a permanentpolarized track magnet, polarized magnetic means associated with thevehicle and operated by the magnetism of said track magnet on themovement of said means through the magnetic field of said track magnetfor opening said air line to permit the escape of air therefrom, andmeans associated with the ends of the poles of said track magnet forcontrolling the magnetic field of said track magnet.

15. In cmnbination with a railway vehicle air line, a polarizedpermanent track magnet havin -ipolarized magnetic moans operated by themagnetism of said traclcmagnc for opening said air line to permit thecscape of the air therefrom on the movement of the vehicle within theIliagfnctic field of said track magnet, manually operated means withinsaid line andicapablc of opcration to permit the restoring: of saidopera tivc means to normal position on themovclncnt of said magneticmeans, without the held of said permanc it rrack n agnct, and meansassociated with ll e ends of the poles of said pcrmaiicnl magilcl' forcontrolling the field of said ,track magnet.

16. A railway signal system including a polarized pcrman ent trackmagnet, a railway vehicle provided with the; usual air line, means forcontrollin the escape of the air under pressure there rom, including amovable valve within said line hav ng a pertion thereof exposed to theair pressure therein, magnetic means, the poles of which are reversed tothe poles of said permanent track magnet for maintaining said valve inposition to close said line, the air under pressure adapted foroperating said valve to open said line on the movement of said magneticmeans within the magnetic field of said rmanent track magnet and theneutralizm of the magnetism thereof, and

means or controlling the magnetic field of said track magnet.

17. A railway signal system including a polarized permanent trackmagnet, a sig-' nal receiver member carried by a railway vehicle andincluding a pair of receiver units successively movable into themagnetic field of said track magnet on the movement of said vehiclethereover, an air line carried by the vehicle and provided with aplurality of outlets, one extending to each receiver, a movable signalcontrol member within each of said units and each normally held againstthe pressure in said line for closing oneoi? said outlets, magneticmeans associated with each of said signal receivers for maine taininsaid members in their latter osition, 1; e poles of said magnetic meansbeing reversed to each other, the last one movable into the magneticfield of said track magnet being reversed to the poles of said trackmagnet, whereby on the movement of said latter receiver within themagnetic field of said track magnet the magnetism will be neutralizedpermitting said line pressure to move said signal control member to openthe outlet controlled thereby, and means for controlling the magneticfield of said track magnet.

18. A railway signal system includin a polarized permanent track magnet,a sig na-lireceiver member carried by a railway vehicle and including apair of receiver-units successively movable'into the magnetic field ofsaid track magnet on the movement of said vehicle thereoveran 311" linecarried by the vehicle and pro ided with a plurality of outlets, oneextending to each receiver, a movable signal control memhorwithin eachof said units and oath against the pressure insaid line for closing oneof said outlets,

magnetic 1neans associnonnally held and the poles of ated with each ofsaid 12m] receivers for,

maintaining said members in their latter position, the poles of saidmagnetic means being reversed to each other, and the poles of the lastone movable into the magnetic field; of said track magnet beingreversedto the moles -0f said track magnet, whereby on the means within saidline capable of manual operation to interrupt the air supply to saidreceiver. means for restoring said operated signal control member tonormal position on the movement of said signal control mem her to apoint without the magnetic field of said track magnet and theinterruption ol the air pressure in said line, and means for controllingthe field of said permanent magnet.

19. A railway signal. system including a permanent polarized trackmagnet, a signal receiver member carried by a railway vehicle andincluding a pair of receiver units successively movable into themagnetic field of said track magnet on the movement of said vehiclethereover, an air line carried by the vehicle and provided with aplurality of outlets, one extending to each receiver, a movable signalcontrol member within each of said units and each normally held againstthe pressure in said line for closing one of said outlets. a movablemember positioned between said receiver units and adapted on themovement of the same within the field of said permanent magnet to beoperated by the magnetism of said permanent magnet to intermittentlyinterrupt the air pressure in said line in advance of said signalcontrol members, magnetic means associated with each of said signalreceivers for maintainin said members in their latter position, the poes of said magnetic means being reversed to each other, and the poles ofthe last one movable into the magnetic field of said track magnet beingreversed to the poles of said track magnet, whereby on the movement ofsaid latter receiver within the magnetic field of said track magnet themagnetism of said track magnet will be neutralized permitting said linepressure to move said signal control member to open the outletcontrolled thereby and means for controlling the field of said permanentmagnet. l

20. A railway signill system including a pair of olarized permanenttrack magnets arranged in spaced relation to each other with their polesreversed, a railway vehicle, a plurality of polarized signal receiverscarried thereby, a signal means controlled thereby, one of saidreceivers adapted for operation by magnetism of one of said magnets onthe movement of the vehicle within the magnetic field thereof. meanscarried by the vehicle and operated by the magnetism of either of saidmagnets during the movement of the same through the magnetic fieldthereof for permitting one of said receivers to remain in operativeposition after being operated bythe ma etlsm of its coiiperating trackmagnet, ependent upon the direction of movement of the vehicle on saidrailway and means associated with the respective track magnets forcontrolling the field thereof. 7

1 21. A railway signal system including a pair of polarized permanenttrack magnets arranged in spaced relation to each other with their polesreversed, a railway vehicle, a plurality of polarized signal receiverscarried thereby, a signal means controlled thereby, one of saidreceivers adapted for operation by the movement of one of said trackmagnets on the movement of the receiver through the field thereof, meanscarried by the vehicle and operated by both of said magnets on themovement of the same through the magnetic field thereof for permittingthe automatic restoring of one of said receivers to normal positionafter being operated by the magnetism of its cooperating track magnetdependent on the direction of movement of the vehicle on said railway,and means associated with each track magnet for controllin the fieldthereof.

22. A railway ve iicle signal system including a controlling unit, anair line having an escape to the atmosphere, a controlling valve withinsaid unit and closing against the pressure in said air line to interruptthe escape of the same to the atmosphere, an armature associated withsaid valve, and a. magnet associated with the unit and arranged with theterminus of the pole pieces thereof extending laterally from oppositesidesof said umt, said magnet attracting said armature to maintain saidvalve normally seated.

23. A railway vehicle signal system including a controlling unit, an airline passing therethrough and having an esca. to the atmosphere, a valveseat within said air line and provided with a restricted port, acontrolling valve associated with said, unit and for cooperating withsaid seat to normally close against the air pressure in said passage,the area. of said valve being greater than that of the restricted portwhereby an increased valve area is exposed to the line pressure whensaid valve is unseated, an armature associated with said valve, a,magnot associated with said unit with the terminals of the pole piecesthereof extending laterally from opposite sides of saidf'unit,

said magnet attracting said armature to maintain said valve normallseated, and means for moving said armature within the field of saidmagnet on the interruption of i the aiilkpresiure in saidl air line. d

24. mi way si a. system inclu ing a railway vehicle, a signal member, apair of polarized magnets o difi'erent strength one associated with therailwayyehicle and the other associated with the trqlok and arrangedwith their poles reversed and one adapted to pass through the magneticfield 0f the other, wheieby the ma etism of the stronger will neutralizet e magnetism of the other and operate said signal member,-

and means coiiperating with the poles of one of said ma nets forcontrolling the magnetic field 0 said magnet.

25. A railway signal system including a railway vehicle, a s1 nalmember, a pair of polarized magnets ofditferent strength one associatedwith the railway vehicle and the other associated with the track andarranged -with' their poles reversed and one adapted to pass through themagnetic field of the other, whereby the magnetism of the stronger willneutralize the magnetism of the other and operate said signal member,

and means associated with its poles for con- I trolling the magneticfield of the stronger magnet.

26. A railway signal system including a railway vehicle, a IEair ofpolarized magnets one associated witthe railway vehicle and the otherassociated with the track and arthe poles of one of said magnets forc0ntrollm the magnetic field of the magnet with w iich said means isassociated.

In testimony whereof we have signed our names to this specification inthe presence of the subscribing Witness.

FOREE UHITTENDEN. o HOWARD S. FOLKER. 'Witness:

D. B. Ricfihnos.

